I'm researching a TV for displaying 3D content from a PC on a passive 3D television. Our current test setup worked fine when connecting a PC to a 1080p passive TV (LG 65LM6200), but due to the nature of the passive technology, images were very jaggy due to the half resolution 540p image to each eye and the FPR (Film-type Patterned Retarder) technology that LG uses.

I am looking in to using LG's new 84" 4K TV, the LG 84LM9600, as it should support full 1080p 3D with their content, essentially halving the 2160p to 1080p in each eye. I'm assuming the source resolution from the PC should be the same because the picture quality loss was happening when the 1080p TV was discarding half of the horizontal resolution.

I'm hoping that this should just be plug and play, but can anyone confirm my guess of the results?

The PC won't need to be configured any differently.

The TV will display a full resolution 1080p image to each eye, alternating each of the 2160 lines with the left and right eye images

There still may be some jagged edges as the is still the FPR between each line and the 1 line gap between each part of each image.

My company is very interested in this technology because of the advantages of using passive 3D, but I don't want to wast almost $20k if this isn't going to work.

The TV will display a full resolution 1080p image to each eye, alternating each of the 2160 lines with the left and right eye images

There still may be some jagged edges as the is still the FPR between each line and the 1 line gap between each part of each image.

My company is very interested in this technology because of the advantages of using passive 3D, but I don't want to wast almost $20k if this isn't going to work.
Thanks!
Sean

*1* The PC should be configured as with any Hdmi1.4a 3DTV and use the automatic 3D mode from Nvidia 3DTV play or AMD HD3D. However, the tech specs seem to indicate the TV cannot be direct-driven at it's native resolution (you cannot output the interleaved picture at 3840x2160). It appears the TV only accepts usual 1080p signals, and does the up-conversion internally. (This means no full resolution 1080p60, only 1080p24)
*2* The TV will not display exactly a Full 1080p picture due to it's internal scaling process up to 3840x2160. LG's 1:1 pixel mapping only claims to support up to normal 1080p, no mention about 3D. The overall quality should be equivalent but if your application requires pixel perfect precision, you might get some surprises since we don't know how LG's scaling system works in 3D mode.
*3* Yes, there will be some jagged edges if you look closely since the viewed resolution is 3840x1080 with black lines in each eye between rows, the effect should be significantly lower than on normal 1080p TVs but it will always be there.

Overall it should work but in my opinion it's a bit too expensive. LG asks for such high price because there is no competition on this market segment.
If you want full 1080p and passive 3D, and a big screen, and accept to use projectors instead of a TV : you could have a look at DIY dual-projection which can accomplish this task starting around 3.000$.

I didn't think I'd try to send the TV's native resolution, but the standard resolution that Blu-Ray would send when frame packing, 1920x2160 (or 1920x2205) as the TV itself would process it the same was as a 3D Blu-Ray.

Assuming I'm sending the resolution from #1, I expect I wouldn't see any artifacts or differences from the current 1080p set we have as that's already processing the image the same way, we're just losing half the resolution.

The cost isn't really an issue as long as it works. I'm hoping I can get some more info, possibly from LG to see if they've changed any of the scaling/processing and pixel mapping in the 4K TV's firmware.

Also, I assume you haven't run in to this issue with your dual projector setup, but after reading a few other forums, it looks like 1080p 3D is limited to 24Hz over an HDMI cable (due to bandwidth limitations or the spec, there was a lot of conflicting info). It's too bad the TV doesn't have a dual-link DVI connection to make it more future proof as it should have more bandwidth than the current HDMI 1.4 spec.

Do you know if it's possible to do at least 3D 1080p @ 30FPS via HDMI 1.4?

The 1080p24 frame packing problem is not a limitation of the spec, it's the minimum requirement.
The hdmi 1.4a spec does allow 1080p30 and even 1080p60 frame packing but it's entirely optional. So far, some Samsung TVs have been found to support 1080p30 frame packing but unless the TV tech specs don't explicitly mention it, it's a lucky find.
For your TV, you should assume it only supports the minimum hdmi spec.

If you're still looking for a solution, there is one now, using an edid override that activates 4k and interleaved mode in 3d vision (optimized for geforce).

There is only a solution to this issue with 4k passive 3D TVs and only in particular sizes with sufficient gaps between adjacent vertical pixels, due to issues with crosstalk.

Sony managed it (just) with the excellent Sony 65X9000A: combining a good contrast VA panel with interleaved FPR, but unless you viewed it perpendicular to the centre of the screen, crosstalk became an issue. Most of the other iterations use IPS panels which have poor contrast, or smaller screens that can't support a full resolution 3D FPR. Any passive 3D screen >= 65" should support full 3D passive resolution.

Only now with the release of the LG 4k OLED, with their much lower fill factor, has the opportunity to achieve full passive 3D on a 55" and above screen been realised AFAIK, along with excellent contrast and deep black level.